It is often desirable to move items or parts of machinery to particular positions, those positions being reached with spatial reliability. In particular, it is sometimes desirable to be able reliably to cycle parts of machinery between particular positions. This would be the case, for example, where it is necessary to form a particular shape in a repetitive manner.
An example of shape forming using machinery is in the food manufacturing and processing industry. Food items such as biscuits often have decorative toppings in particular shapes. For efficiency, throughput and consistency reasons, mechanical deposition systems are often used to deposit such decorative toppings.
Such mechanical deposition systems may include a moveable deposition manifold arranged on a conveyor belt. The deposition manifold is moveable in the sense that it can be made to describe a particular shape with respect to food items travelling along the conveyor belt. Typically, the deposition manifold is moveable independently of the conveyor belt. The movement of the manifold is powered and controlled by suitable arrangements of linear drives, for example suitable arrangements of ball screws and pulleys.
More generally, it is often desirable to perform a repetitive process on a series of similar items. Typically, items are transported around a production facility using a conveyor belt or similar means. If the items are relatively small, or if the production line has a large output, the items may be arranged in ranked rows on the conveyor belt.
Many processes in production lines require that the position of the items to be processed is known with some spatial reliability. Typically, items on a conveyor belt are prone to move a little on the conveyor, due to vibrations etc. Movement apparatus can be used to move the items to a predetermined position on the conveyor, ready for a subsequent processing step. The movement apparatus typically is powered and controlled by suitable arrangements of linear drives, as for the deposition manifold above.
These arrangements of linear drives are usually bulky and difficult to install or retro-fit to existing production lines. In addition, it is difficult to operate movement of the manifold using such arrangements at speeds necessary for large volume production.
In order to address the problems outlined above, the present invention provides, in a first aspect, a movement output apparatus for controllably moving a movement output means in at least two spatial dimensions, the apparatus including:                a cog means with a first diameter;        a ring with a track formed on or near the surface of the ring, the track having a second diameter which is larger than the first diameter;        
wherein:
the cog means is rotatable by first driving means;
the ring is rotatable by second driving means;
the cog means is arranged to move, in use, along the track; and
the movement output means is attached to the cog means whereby, in use, movement of the cog means effects movement of the movement output means, and the movement of the movement output means is controllable by control of the first and second driving means preferably to produce a substantially linear movement of the movement output means.
Using the apparatus, the movement of the movement output means can be controlled to describe a particular two dimensional shape by suitable control of the first and second driving means.
Preferably, the ring defines a rotation plane and the cog means is preferably rotatable by the first driving means, about a first axis which is typically substantially perpendicular to the rotation plane.
Preferably, the ring is rotatable by the second driving means about a second axis which is typically substantially perpendicular to the rotation plane.
Preferably the cog means is rotatable relative to the track about a third axis which is typically substantially perpendicular to the rotation plane. This rotation of the cog means about the third axis is typically brought about due to an interaction between the cog means and the track.
Preferably, the third axis is substantially parallel to, but typically substantially not co-linear with, the second axis.
Typically, the cog means and the track each have teeth which are meshable together. Preferably, at least one of the cog means and the track have a substantially circular configuration. More preferably, both the cog means and the track each have a substantially circular configuration.
In some embodiments, the ring may be replaced by a partial ring. Using such a configuration, the track would preferably be a non-continuous arcuate track.
In preferred embodiments of the invention, the relationship between the first and second diameters is such that rotation of the cog may cause (possibly in conjunction with rotation of the ring) a point on the cog (usually a point on the perimeter of the cog) to describe a substantially straight line. Preferably, the first diameter is approximately one half of the second diameter. Using such a cog arrangement, the movement output means may be positioned with respect to the cog means such that the movement output means may describe substantially any shape in two dimensions within a particular size range.
Preferably the movement of the movement output means is controllable to produce linear movement along wither or both of two mutually perpendicular axes. More preferably in use the two axes are respectively substantially horizontal and substantially vertical.
The movement output means (which may be e.g. a cam follower) may be attached to the cog means such that the centre of the movement output means is a distance from the axis of rotation of the cog means which is substantially equal to the first diameter. In one embodiment, the movement output means is substantially cylindrical and its central axis is substantially parallel to the axis of rotation of the cog means and its central axis is a distance from the axis of rotation of the cog means which is substantially equal to the first diameter.
Preferably, the cog means is rotatably mounted on a first shaft. Preferably, the first shaft is eccentrically mounted with respect to an output rotation axis of the first drive means. Typically, therefore, operation of the first drive means rotates the first shaft eccentrically. Consequently, the cog is forced to rotatably travel around the track.
Preferably, the ring and track together form an internal gear.
Preferably, the output movement means is connected to a movement transmission means.
Preferably, the apparatus further includes control means for control of the second driving means, the control means operating according to a predetermined set of instructions. Typically, the control means includes a suitably programmed computer. Preferably, the control means controls the first driving means.
Preferably, the cog means and/or ring are replaceable by a cog means and/or ring of different dimensions in order for the movement output means to controllably describe a shape in two dimensions in a different size range.
In preferred embodiments, the apparatus further includes a controllable counterbalancing assembly. Typically, such an assembly includes an arrangement of masses which are moveable via one or more driving means. Preferably, the arrangement of masses is moveable in order to substantially reduce vibrations in the apparatus caused by movement of other parts of the apparatus. Preferably, the arrangement movement is controlled by the control means. The arrangement movement may be adapted to be a mirror image movement of the movement of those parts of the apparatus which cause, in use, undesirable vibrations.
In a second aspect, the present invention provides a repetitive processing apparatus including a movement output apparatus according to the first aspect, and further including a repetitive processing device for repeated performance of a particular process, wherein the repetitive processing device is connected to the movement output means, and in use the position of the repetitive processing device is controllable by control of the position of the movement output means.
Preferably, the apparatus further includes moveable conveyor means, whereby articles on which a particular process is to be performed are moveable with respect to the apparatus.
In a third aspect, the present invention provides a deposition apparatus including any apparatus according to the first or the second aspect.
In a fourth aspect, the present invention provides a foodstuff processing apparatus including any of the features of the second aspect and typically including any features of the third aspect, wherein the repetitive processing device is a foodstuff deposition manifold, the manifold being, in use, controllable to deposit foodstuff in a pre-programmed shape.
Preferably, the food stuff deposition manifold is capable of performing at least approximately 40 cycles per minute. More preferably, it is capable of performing up to around 100 cycles per minute or more, most preferably up to around 400 cycles per minute or more.
Preferred embodiments of the invention will now be described, by way of example only, with respect to the accompanying drawings, in which: